Gas chromatography coupled with mass-spectrometry (GC-MS) has long been the workhorse for environmental analysis. Fragmentation using traditional electron-ionization (EI) provides a wealth of structural information. Substantial archived library information is available to aid the analyst with unknown identification. Tandem quadruple (MS/MS) and quadruple time of flight systems (qTOF MS) offer better sensitivity and selectivity compared with single quadruple systems. Although these techniques have been successfully used for GC-MS using EI, alternative methods of ionization may be more suitable for trace level quantitative and qualitative analysis. Over the last few decades, LC-MS methods have become a very important environmental analysis tool using electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI). An important advantage to these ionization modes is that a molecular ion or protonated molecular ion can usually be produced at very high abundance in the first quadruple. With EI, this is not usually the case; one must choose among many lower abundance fragment ions for transmission to the second quadrupole or TOF. Thus, higher sensitivity and selectivity are possible with ESI or APCI. Atmospheric pressure ionization mass spectrometry for GC (APGC) provides mass-spectrometric data comparable to APCI data used for LC-MS. As in tandem LC-MS, cone-voltage can be optimized to produce mainly molecular ion (for quantitative analysis) or in-source fragmentation (for qualitative analysis). As in tandem LC-MS, collision cell energy can be optimized to produce fragments best suited for quantitation. Another advantage is that the same mass-spectrometer can be used for both LC and GC applications. In this presentation we will discuss some applications of this new APGC technology including brominated flame retardants (BFRs), pesticides, and non-purgeable volatile organic compounds (VOCs).

Atmospheric pressure ionization mass spectrometry for GC (APGC): An enabling technology for detection of contaminants of concern

248th National Meeting (2014)

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